The effectiveness is generally zero. Nada. Efess. Useless. The “science” behind homeopothy is complete garbage.
There have been many careful studies showing that the effects of homeopathy are similar to that of a placebo. Of course, proponents of homeopathy always find fault in the studies.
It’s possible that certain alternative therapies have some value, but that value has not been proven yet. If the value of any alternative therapy is ever proven, it will then simply be called “Medicine” (and not “Alternative/Homeopathic/Naturopathic/etc Medicine”).